Electrosurgical generator

Abstract

A solid-state electrosurgical generator is disclosed which provides three separate output circuits that may be operated from a single common power source. One of the output circuits produces an output electrical waveform which is optimized for cutting and coagulation with monopolar electrodes. Another circuit provides a waveform which is optimized for cutting and coagulation with bipolar electrodes. The other electrosurgical circuit produces an output electrical waveform which is optimized for fulguration. The output circuits produce the optimized waveforms by appropriately processing electrical power provided by a D.C. power source. In order to do this, the output circuits may be connected to the power source by means of four semiconductor switches may be arranged in either a bridge configuration for one output circuit or in a series arrangement for the other output circuit. The switches are, in turn, controlled by a timing circuit which provides different timing waveforms to the switches depending on their configuration.

What is claimed is: 
     
       1. In an electrosurgical generator for performing a plurality of electrosurgical operations having a D.C. power source, output circuitry for connection to a patient and means controllable by an operating surgeon for selecting one of said electrosurgical operations, the improvement comprising: a plurality of switches;   means responsive to said selecting means for connecting said switches in a bridge configuration;   means responsive to said selecting means for connecting said bridge across said power source;   means responsive to said selecting means for connecting said output circuitry across said bridge; and   means responsive to said selecting means for generating timing signals to control said switches to selectively connect said output circuitry to said power source.   
     
     
       2. In an electrosurgical generator, the improvement according to claim 1 wherein said bridge has four arms, one of said switches being located in each arm, and said timing signal means alternately operates pairs of said switches in diagonally-opposite arms to connect said output circuitry to said power source. 
     
     
       3. In an electrosurgical generator, the improvement according to claim 1 further comprising means responsive to said selecting means for reconfiguring said switches to place said output circuitry and said switches in series across said power source. 
     
     
       4. In an electrosurgical generator, the improvement according to claim 3 wherein said timing signal means simultaneously operates all of said switches when said switches and said output circuitry are connected in series across said power source. 
     
     
       5. In an electrosurgical generator for performing a plurality of electrosurgical operations having a D.C. power source, a first output circuit connectable to a patient for performing an electrosurgical fulguration operation, a second output circuit connectable to a patient for performing electrosurgical dessication or cutting operations, and means controllable by an operating surgeon for selecting one of said electrosurgical operations, the improvement comprising; a reconfigurable switching network;   means connecting said switching network to said power source;   first means responsive to said selecting means for configuring said switching network to connect said first output circuit directly across said power source; and   second means responsive to said selecting means for configuring said switching network to connect said second output circuit directly across said power source.   
     
     
       6. In an electrosurgical generator, the improvement according to claim 5 wherein said switching network comprises a plurality of switches and said first configuring means is responsive to said selecting means for connecting said switches in series with said first output circuit. 
     
     
       7. In an electrosurgical generator, the improvement according to claim 6 wherein said second configuring means is responsive to said selecting means for connecting said switches in a bridge configuration across said power source and said generator further comprises means responsive to said selecting means for connecting said second output circuit across said bridge configuration. 
     
     
       8. In an electrosurgical generator, the improvement according to claim 5 wherein said first output circuit comprises a parallel L/C network and said second output circuit comprises a transformer. 
     
     
       9. In an electrosurgical generator, the improvement according to claim 8 wherein said parallel L/C network comprises a capacitor connected across the primary winding of a transformer. 
     
     
       10. An electrosurgical generator for performing a plurality of electrosurgical operations comprising: a D.C. power source,   a first output transformer having a primary winding and a secondary winding connectable to a patient for performing an electrosurgical fulguration operation;   a capacitor connected across said primary winding of said first output transformer;   a second output transformer having a primary winding and a secondary winding connectable to a patient for performing electrosurgical dessication or cutting operations;   control means operable by an operating surgeon for selecting one of said electrosurgical operations;   a plurality of switches;   first mode means responsive to said control means for connecting said switches in series with said primary winding of said first output transformer across said power source;   second mode means responsive to said control means for connecting said switches in a bridge configuration across said power source and for connecting said primary winding of said second output transformer across said bridge.   
     
     
       11. An electrosurgical generator according to claim 10 wherein said bridge configuration comprises four switches, two pairs of said switches being connected in series to two midpoints and each of said pairs of switches being connected in parallel. 
     
     
       12. An electrosurgical generator according to claim 11 wherein said primary winding of said second output transformer is connected across said midpoints of said bridge configuration. 
     
     
       13. An electrosurgical generator according to claim 12 further comprising timing means responsive to said control means for selectively operating said switches to selectively connect said first and second output transformers to said power source. 
     
     
       14. An electrosurgical generator according to claim 13 wherein said timing means is responsive to said control means for selectively operating switches connected in diagonally opposite arms of said bridge configuration. 
     
     
       15. An electrosurgical generator according to claim 14 further comprising an output filter circuit connected to said secondary winding of said second output transformer to eliminate high-frequency components in the output waveform.